Management of Acute Idiopathic Bell's Palsy
Immediate Treatment: Corticosteroids Within 72 Hours
Start oral corticosteroids within 72 hours of symptom onset for all patients ≥16 years old—this is the only proven treatment that significantly improves facial nerve recovery. 1
Recommended Steroid Regimens (Choose One):
- Prednisolone 50 mg once daily for 10 days (no taper needed), OR 1
- Prednisone 60 mg once daily for 5 days, followed by a 5-day taper 1
Evidence Supporting Steroids:
- 83% complete recovery at 3 months with prednisolone vs. 64% with placebo (NNT = 6) 1
- 94% complete recovery at 9 months with prednisolone vs. 82% with placebo (NNT = 8) 1
- No benefit if started after 72 hours—the treatment window is critical 1, 2
Antiviral Therapy: Limited Role
Never prescribe antivirals alone—they are completely ineffective as monotherapy and delay appropriate corticosteroid treatment. 1, 2
Optional Combination Therapy:
- May add valacyclovir 1 g three times daily for 7 days OR acyclovir 400 mg five times daily for 10 days to steroids within 72 hours 1
- Provides modest additional benefit: 96.5% recovery with combination vs. 89.7% with steroids alone (absolute benefit +6.8%) 1
- This is classified as an "option" rather than a recommendation due to the small incremental gain 1
Eye Protection: Mandatory for All Patients with Impaired Eye Closure
Implement aggressive eye protection immediately to prevent permanent corneal damage—this is non-negotiable. 1, 2
Specific Eye Protection Measures:
- Lubricating eye drops every 1-2 hours while awake 1
- Ophthalmic ointment at bedtime for sustained moisture 1
- Eye taping or patching at night with careful instruction on proper technique to avoid corneal abrasion 1
- Sunglasses outdoors to protect against wind and debris 1
- Urgent ophthalmology referral if severe impairment with complete inability to close the eye 1
Diagnostic Testing: What NOT to Do
Do not order routine laboratory tests or imaging for typical Bell's palsy—they delay treatment without improving outcomes. 1, 2
When to Consider Testing:
MRI with and without contrast only for atypical features: 1
- Bilateral facial weakness
- Isolated branch paralysis (forehead spared)
- Other cranial nerve involvement
- Progressive weakness beyond 3 weeks
- No recovery after 3 months
- Recurrent paralysis on the same side
Electrodiagnostic testing (ENoG/EMG) may be offered only to patients with complete facial paralysis at 3-14 days post-onset 1
Follow-Up and Referral Triggers
Mandatory 3-Month Reassessment:
Refer to a facial nerve specialist if facial recovery is incomplete at 3 months after symptom onset. 1, 2
Urgent Referral at Any Time Point:
- New or worsening neurologic findings (suggests alternative diagnosis like stroke, tumor, or CNS pathology) 1
- Development of ocular symptoms (requires ophthalmology referral to prevent corneal damage) 1
- Progressive weakness beyond 3 weeks (red flag for alternative diagnosis) 1
Special Populations
Children:
- Better prognosis than adults with higher spontaneous recovery rates (up to 94%) 1
- Steroid benefit is inconclusive in pediatric patients—no high-quality pediatric-specific trials exist 1
- Consider prednisolone 1 mg/kg/day (max 50-60 mg) for severe/complete paralysis after shared decision-making with caregivers 1
Pregnant Women:
- Treat with oral corticosteroids within 72 hours using individualized risk-benefit assessment 1
- Pregnancy is not a contraindication to steroids 1
- Eye protection measures are essential and safe in pregnancy 1
Diabetic Patients:
- Diabetes is not a contraindication to corticosteroids—the therapeutic benefit outweighs the risk of temporary hyperglycemia 1
- Monitor capillary blood glucose every 2-4 hours during the first few days of steroid therapy 1
- Proactively adjust diabetes medications: increase basal insulin and add/increase prandial insulin 1
- Consider adding NPH insulin concurrent with morning steroid dose (peaks 4-6 hours later, matching hyperglycemic effect) 1
Prognosis and Natural History
Expected Recovery Timeline:
- Incomplete paralysis at presentation: up to 94% complete recovery 1, 3
- Complete paralysis: approximately 70% complete recovery within 6 months 1
- Most patients begin showing recovery within 2-3 weeks 1
- Complete recovery typically occurs within 3-4 months 1
Poor Prognostic Factors:
- Complete paralysis at presentation 3
- ENoG showing <10% nerve response amplitude 1
- Age >60 years 4
- Diabetes mellitus 4
Interventions NOT Recommended
Do not offer the following—they lack proven benefit or have insufficient evidence: 1, 2, 5
- Physical therapy: no proven benefit over spontaneous recovery 1
- Acupuncture: poor-quality trials with indeterminate benefit-harm ratio 1
- Electrical nerve stimulation: no specific recommendation due to lack of evidence 5
- Surgical decompression: not advised except in rare, highly selected cases at specialized centers 1
Critical Pitfalls to Avoid
- Delaying steroids beyond 72 hours eliminates their effectiveness 1, 2
- Using antiviral monotherapy is completely ineffective and delays appropriate treatment 1, 2
- Inadequate eye protection can lead to permanent corneal damage 1
- Failing to refer at 3 months delays access to reconstructive options 1
- Missing atypical features (bilateral weakness, forehead sparing, other cranial nerve involvement) suggests alternative diagnoses requiring imaging 1
- Ordering routine labs/imaging for typical presentations increases costs without benefit 1, 2